A key divide exists between how software developers and ordinary users experience bugs, according to a detailed analysis by programmer Dan Luu. Many people encounter the same bugs repeatedly but fail to notice them, while experienced bug-spotters can identify hundreds to thousands of bugs per week across various products.
Luu describes this phenomenon as “bug blindness”—a tendency for people to stop seeing flaws in products they use regularly or have invested in emotionally. He notes that after pointing out bugs to friends over several weeks, many begin noticing problems they previously overlooked.
The gap becomes particularly acute in enterprise software and widely-used platforms. Luu has been asked by company executives to evaluate products specifically because of his reputation for spotting issues others miss. Sometimes he finds nothing concerning. More often, he discovers mild to moderate problems. In severe cases, products appear fundamentally non-functional without non-intuitive workarounds—yet internal company discussions often describe the same products as working well.
Luu initially wondered if he was triggering unusual edge cases, but subsequent product launches that failed due to the exact issues he identified suggested otherwise. He notes that large language models can now replicate normal user behavior and reproduce these problems across diverse scenarios.
Examples include search engine results that are “full of low-quality SEO spam as well as some sites that were actually scams,” according to Luu’s analysis of Google, Bing, and Kagi. While observers largely agreed with his assessment of Google and Bing, some disputed his Kagi evaluation—yet when those people shared their actual search results, the results contained the same deficiencies Luu had noted.
The Blackboard course management software provides another illustration. Despite being described internally as well-liked, Blackboard was widely disliked by students and professors. A December 2011 Fast Company survey found 93% of respondents “hate” the company. When Luu mentioned this to a Blackboard employee, they expressed confusion, believing the software was actually beloved.
Luu attributes part of this disconnect to how people who are fans of products tend to become blind to their faults. Product enthusiasts may dismiss negative reliability data or overlook obvious quality issues when presented with them. The phenomenon extends to forum discussions where users insist products work well despite widespread complaints and documented problems.
Key facts
- Dan Luu observes hundreds to thousands of bugs per week while most people don’t notice the same flaws
- Bug blindness is a tendency to stop noticing recurring problems in products used regularly
- A 2011 Fast Company survey found 93% of respondents ‘hate’ Blackboard, despite some internal staff believing it was well-liked
- Luu has been specifically hired by executives to evaluate products because of his reputation for identifying issues others miss
- Search engines returned results full of SEO spam and scams according to Luu’s analysis